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Finding the Fourth Proportional to 390.82, 585.85 and 279.64

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Solution

The fourth proportional to 390.82, 585.85 and 279.64 is: 419.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.82 : 585.85 = 279.64 : x
  2. Step 2: Convert to fraction form
    390.82/585.85 = 279.64/x
  3. Step 3: Cross multiply
    390.82x = 585.85 × 279.64
  4. Step 4: Simplify right side
    390.82x = 163,825.70
  5. Step 5: Solve for x
    x = 163,825.70/390.82
  6. Step 6: Final answer
    x = 419.19

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.